Peanut butter and jelly may have been your go-to lunch as a child (cut into four triangles and never squares, obviously). And if you find yourself gravitating toward it as an adult, too. We don't ...

PB&J is among the cheapest sandwiches you can make, packs in a substantial amount of protein, and satisfies picky kids and nostalgic adults alike. But like most classics, this lunch-box mainstay has a ...